This proposal requests funds to enable young investigators to attend the 20th International Herpesvirus Workshop in Groningen in the Netherlands, July 29-August 3, 1995. This workshop is the premier scientific meeting for herpes virologists. The strength of the workshop rests on the support and participation of leading researchers, promising young investigators and students in training. The forum is truly international, with broad based world wide attendance. The human herpesviruses are medically important because they cause a wide range of diseases. These include skin and eye ulcerations (HSV-1), genital lesions (HSV-2), meningoencephalitis (HSV-1, HSV-2), infectious mononucleosis (EBV), chicken pox and shingles (VZV), and roseola (HHV-6). Congenital CMV infections are a major cause of mental retardation and birth defects, including hearing loss. Neoplasias have been associated with EBV, including Burkitt's lymphoma, nasopharyngeal carcinoma, and B- cell neoplasia. All of the human herpesviruses persist for life and therefore pose significant problems in the treatment of the immunologically suppressed. Cancer patients, organ transplant recipients, and AIDS patients are particularly susceptible to reactivation of latent HSV, EBV, CMV, and VZV resulting in increased morbidity and mortality. CMV retinitis and pneumonitis are examples seen frequently in AIDS patients. Herpes zoster and post herpetic neuralgia are problems in the elderly. Animal herpesviruses have significant economic importance to the poultry (Marek's disease virus), swine (Pseudorabies virus), dairy (bovine rhinotracheitis virus), and horse breeding (equine herpesviruses) industries. In addition, these veterinary herpes viruses serve as model systems for studying the basis of herpesvirus pathogenesis, such as oncogenicity in Marek's disease virus and herpesvirus saimiri (monkeys). Future medical applications will include designing recombinant herpesvirus vectors for gene therapy. Workshop sessions will be divided into the following topics: regulation of gene expression, DNA replication, enzymes and non-structural proteins, latency and pathogenesis, immune response to infection, virus entry and assembly, virus receptors and glycoproteins, epidemiology and diagnostics, antivirals and vaccines, and gene therapy.